Employee Stock Benefit Plans - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based compensation:
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	0.00%		0.00%
Award expiration period	10 years
Vesting percentage	100.00%
Shares Authorized	116,627,000
Maximum awards paid annually	$ 5,000,000
Shares Available for Grant	23,441,000
Stock options granted, weighted average exercise price (USD per share)	$ 0		$ 6.46
Restricted stocks and restricted stock units, granted, weighted average exercise price (USD per share)	$ 11.29	$ 10.55	$ 6.79
Stock options, exercises in period, aggregate intrinsic value	$ 7,616,000	$ 38,248,000	$ 38,958,000
Restricted stocks and restricted stock units, exercised, aggregate intrinsic value	32,872,000	$ 44,812,000	$ 41,057,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested	76,986,000
Stock options, grants in period, weighted average grant date fair value (USD per share)			$ 3.04
Total unamortized share-based compensation	$ 51,602,000
Total unamortized share-based compensation, period for recognition	2 years 1 month 6 days
Maximum employer contribution percentage	50.00%	50.00%	50.00%
Annual contribution limit per employee	$ 6,000	$ 6,000	$ 6,000
Retirement plan expense	$ 8,750,000	$ 6,756,000	$ 5,411,000
Restricted stock and restricted stock units
Share-based compensation:
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	0.00%	0.00%	0.00%
Vesting percentage	200.00%
Selling, general and administrative expense
Share-based compensation:
Share-based compensation expense	$ 45,242,000	$ 33,799,000	$ 37,482,000
2006 Incentive Plan
Share-based compensation:
Shares Authorized	71,669,000
Shares Available for Grant
2015 Incentive Plan
Share-based compensation:
Shares Authorized	42,731,000
Shares Available for Grant	23,145,000
Minimum
Share-based compensation:
Award vesting period	3 years
Award expiration period	5 years
Maximum
Share-based compensation:
Award vesting period	4 years
Award expiration period	10 years
Maximum | Stock option and stock appreciation rights
Share-based compensation:
Shares Authorized	10,000,000
Director [Member] | Maximum | Stock option and stock appreciation rights
Share-based compensation:
Shares Authorized	10,000,000